Kirkpatrick-Steger K, Vander Linden S, Gormezano I
Department of Psychology, University of Iowa, Iowa City 52242.
Pharmacol Biochem Behav. 1992 Feb;41(2):333-42. doi: 10.1016/0091-3057(92)90107-q.
The present investigations sought to determine the effects of 3,4-methylenedioxyamphetamine (MDA) on: 1) differential conditioning of the rabbit's nictitating membrane response to the serial compounds A-X-US (tone-light-reinforced compound) and B-X (white noise-light-unreinforced compound) by examining differential responding to A and B and their conditional control over responding to X within the compounds (Experiment 1); and 2) the ability of the compound stimuli and their components to modify the amplitude of the unconditioned nictitating membrane response (Experiment 2). Experiment 1 revealed that MDA decremented differential responding to the serial compounds and their A and B components, while enhancing conditioned responding to the X component. In addition, Experiment 2 indicated that MDA attenuated reflex modification to the compounds and their A and B components, but facilitated reflex modification to X alone. The results of these experiments indicated that MDA operated to alter the intensity, distinctiveness, and persistence (short-term memory) of stimulus representations.
